The present invention relates to a new and improved construction of an apparatus for forming portions of lather or soap foam.
Generally speaking, the lather forming and dispensing apparatus of the present development is of the type composed of a supply container for an aqueous soap solution. Furthermore, such apparatus contains a soap solution-dosing pump and a compressed air-membrane pump, each of which pumps can be actuated by a single lever or actuator. The compressed air-membrane pump is provided with a membrane or diaphragm piston and there is also provided a return or restoring spring as well as a mixing chamber for the formation of the lather or soap foam.
As is well known soap dispensers of the most different designs are employed in public and private washrooms, toilets and the like. Among these prior art soap dispensers there are known lather producing soap dispensers employing a propellant gas composed of dichlorodifluoromethane (more commonly known under the Trademark "FREON 12")and the widespread use thereof has been restricted because of enviromental reasons.
Furthermore, from European Patent Application No. 0019582, published Nov. 26, 1980, an the aforementioned U.S. Pat. No. 4,349,131 there is known in this technology an apparatus for dosing and forming lather or soap foam and which apparatus is of the general type discussed above. More specifically, such prior art dispenser equipment comprises a single lever for simultaneously driving a piston of a soap solution-dosing pump and a membrane pump for generating compressed air. This compressed air is forced into the soap solution available in a dosed quantity within a mixing chamber or compartment, by means of a perforated wall of a line or conduit. There is formed a coarse-bubble soap foam which is subsequently expressed through a porous body, then homogenized and compacted.
In practice this solution has been found to be extremely economical in terms of the consumption of soap. On the other hand, it has been found that the soap foam, especially when the dispensing apparatus is not used for a longer period of time, tends to dry and cake at the region of the outlet opening of the dispensing apparatus. This, in turn, has a detrimental effect upon the functional reliability of the dispensing apparatus.